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arXiv · 1506.01736

High-fidelity initialization of long-lived quantum dot hole spin qubits by reduced fine-structure splitting

Alistair J. Brash·Luis M. P. P. Martins·Feng Liu·John H. Quilter·Andrew J. Ramsay·Maurice S. Skolnick·Anthony M. Fox
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Abstract

We demonstrate an on-demand hole spin qubit initialization scheme meeting four key requirements of quantum information processing: fast initialization (1/e ~ 100 ps), high fidelity (F > 99%), long qubit lifetime $(2T_{1}>T_{2}^{*}\simeq10\:\mathrm{ns})$, and compatibility with optical coherent control schemes. This is achieved by rapidly ionizing an exciton in an InGaAs quantum dot with very low fine-structure splitting at zero magnetic field. Furthermore, we show that the hole spin fidelity of an arbitrary quantum dot can be increased by optical Stark effect tuning of the fine-structure splitting close to zero.

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Alistair J. Brash, Luis M. P. P. Martins, Feng Liu, John H. Quilter, Andrew J. Ramsay, Maurice S. Skolnick, Anthony M. Fox. 2015-09-25. High-fidelity initialization of long-lived quantum dot hole spin qubits by reduced fine-structure splitting. https://doi.org/10.1103/physrevb.92.121301

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